Trevor Garfield, a former teacher from New York went into work one day never expecting to lie near death. That was the case as he was stabbed by a disgruntled student.
Trevor, after the attack, must take a job substitute teaching in the Valley in California. He meets Dave Childress and Ellen Henry, two teachers who offer their help and support to him. On his first day, he has a problem and walks into the wrong class. When he finally gets to the right class, Benny Chacon's goons leave, as they are not in his class.
Benny and his gang give Garfield a hard time, but when Benny is found dead, all peoples suspicions are raised a little. Cesar feels it was Garfield, and become the new leader of the gang. Cesar starts warfare with Garfield, and Garfield gets back at him, using his street smarts to get back at Cesar. The war of words and actions escalates when Rita is assaulted by Cesar's goons at a picnic one day, and it comes to a head when there is a school board meeting to discuss the death of Benny Chacon.
Trevor inadvertanely admits to Dave that he killed Benny and chopped off Cesar's finger. Trevor is called into Principal Garcia's office the next day, and is given the pink slip over allegations he had sex with Rita.